Materials based on plywood
The basic materials for this group of products are veneers of various wood types, which are gained in peeling processes from tree trunks as large and round as possible and then, after drying, pressed into new products with the help of resin binders, high temperatures and high pressure.
In plywood manufacturing, each veneer or “ply” is placed at right angles onto the layer below and glued together. To prevent the board from warping, the top plies must always have the same grain direction and the board must be structured symmetrically.
In LVL boards (laminated veneer lumber), all the veneers are laid in the same grain direction, though for greater thicknesses veneers at right angles (max. 15%) do provide better stability and strength.
Whereas these two examples are usually used as panels and, due to veneer dimensions, limited to approx. 2.50 x 1.25 m, Parallam PSL (parallel strand lumber) is a beam-like product which is manufactured endlessly from long and narrow strips of veneer in different cross-sections and can subsequently be cut to size and shaped.
Plywood is also used in furniture. A widespread modified form of this material commonly used in central Europe is block plywood, the standard name being block board. The boards are made up of a core of softwood strips sandwiched between two outer layers of veneer, resulting in a strong yet light panel with outstanding board qualities.